Category: Turners Meets
(page 1 of 2)

As usual, Denny put on a fascinating and informative meeting making a bowl from a walnut log.He starts with half of a log, then screws a cardboard circle to it to help cutting out a blank on the band saw. After turning the outside , and adding a dovetail, he flips it over.

We gave Denny a break this month and held the turners meet at Marvin Stoltzfus shop. Marvin invented a tool for turning perfect spheres on a lathe. It took him 2 years and several proto types before he perfected it, and sold the patent.

He started with a maple blank. It was his goal to make a baseball and stand in one hour. But with all the explaining it took him a little longer. After turning the ball he adds the stitching with a wood burning tool to make it look real, and then puts a team logo on the stand.

Denny showed both open and closed segmented bowl turning. He feels that open segments are actually easier than closed ones. He starts with a program in which he designs the bow or vase. The program then produces a table showing all the segments and there size to the third decimal place. For both types, open and closed, each segment has to be cut at an exact angle. Denny has tried all kinds of miter gauges, but the most accurate are the sleds he builds himself. A dedicated sled for each angle. For a 12 segmented bowel that is 15 deg.

For a closed segment bowl he clamps each segment in a hose clamp to hold it together while the glue dries. He likes to use Gorilla glue. To flatten the surface of the first layer he hot glues it to a plate on the lathe and turns it flat. Each successive layer is glued to the previous one using a home made cone to center it. Each layer has to be flattened and thicknessed exactly.

Open segmented bowels are done quite differently. Each segment is glued on at he lathe using another one of his custom home made jig to locate it at the exact angle and distance from center.

Any glue that squeezes out has to be cleaned up immediately. Then the layer is flattened and thicknessed just like with the closed segments. If the neck of the vase is narrow he turns the inside of it as he adds layers. We have all seen the beautiful results of Denny’s work, and now we have a idea of the patients and care that goes into making one

We had the biggest turnout ever at the January turners meet. Denny demonstrated how to make a bowel from a single piece of wood. The trick is to cut out concentric circles with the blade at an angle and then glue them together in reverse order. You can do this on a band saw if you make half circles and then glue them back together. Or, if you have a scroll saw you can cut them out without having to cutting them in half. The bowels end up in a basic funnel shape if you use one board, but you can get other shapes if you use two boards and take every other layer from each board. You can add variety to the piece by gluing together different kinds of wood into a single board.

For this meeting, Denny presented his own special tips and techniques for producing segmented turnings. As expected, segmented turnings can be quite complex, so Denny broke down his thinking into separate sections for this meeting.
He began with recommending a favorite book of his, “Segmented Wood Turning,” by William Smith.
Notably, he pointed out some charts and angles in the back of the book. Angles can be confusing, so remember there are 360° in a full circle. Tonight’s project has 24 segments, so some simple math has that 360° divided by 24 segments yields 15° each. What is not apparent at first glance is that the 15° for each segment gets divided in half, so each side of each segment gets 7.5°. Keeping that in mind for now, Denny goes on to point out that expansion and contraction in the bottom of any bowl can be a problem, since the wood grain in the bottom generally runs in one direction while the grain of the side segments runs around the bowl with a differing angle for each segment.
Next, Denny brought out his laptop and showed us how his favorite turning software, “Wood Turner’s Studio,” which Denny says is simple and fast to use. The software was originally developed by Craft Supplies USA, on the web at: http://www.woodturnerscatalog.com/b/39/Craft-Supplies-USA.
Interestingly, the software is no longer available there, but other sources exist. A screen shot is shown below.
A web search shows a site called “ software.informer” has the software available on this site: http://woodturner-studio.software.informer.com/1.0/ (sorry, neither I nor the club can endorse any software or online download, but if you have success with this, you can let the members know.)
As Denny was demonstrating the drag and shift nature of this software, he informed us of another detail, called padding. Since the software computes segment sizes, and their glue up can be critical, it is to the advantage of the turner to allow some “fudge factor” or extra amount of wood to be turned off in the bowl building process. Speaking of a fudge factor is a good segue to Denny’s next topic of jigs to control the cutting and building up process.
To illustrate, if on a closed segmented bowl with 24 segments, each with 7.5° cuts at each end, suppose that each cut was off by only 1/10° each. As the error multiplies around each layer of the bowl, 24 segments would sum to 2.4°. That means that either the bowl would have gaps in it, or that the segments would be too long. Predictably, Denny next showed off some of the jigs used to make his cuts.
For an open segmented bowl, small angle differences become invisible in the gaps as long as the gaps are uniform. Here, he is satisfied with his Inca miter gauge accurate to 1/10°. He groups several layers of the bowl to allow ripping with identical widths. Then he cuts the angles on the table saw with the miter gauge. The length of the 24 segment pieces is dialed in by small adjustments to his stop. He cut, measured, and adjusted the miter stop with an automotive feeler gauge. When satisfied, he makes 24 pieces, flipping the stock over after each cut. He allows a little extra thickness that is trimmed off with a jig mounted on his lathe at a later step. He lightly sands the pieces by hand to knock off the fuzz.
Next Denny demonstrated how he gets each layer to be the exact final thickness required in the layer he is working on. For this, he worked on a layer previously glued up on the work piece that had sufficient time for the glue to dry. Here he mounted a hand held router in a wooden strap mounted in turn to a
cross slide vice. The router had a straight trimmer bit, and the entire assembly was mounted on the lathe bed. The lathe was turned in the reverse direction to the router bit’s direction and a low rpm was selected. This jig quickly removed the extra stock down to the intended 1/8” thickness.
Denny’s next jig is a Plexiglas round set on the outboard side of the lathe. The Plexiglas has degree markings all around, and Denny used a vertical alignment piece that indicates then the lathe was turned to the desired angle, at which point he clamped the alignment piece in place and glued on the first of the next layers of segments. He likes Gorilla Glue in a one ounce dispenser bottle. One can find product details here: http://www.gorillatough.com/gorilla-wood-glue.
Denny says he can disregard the recommended clamp time of 15 to 20 minutes, and reduces that down to less than a minute for each piece. He says that once the glue wets the wood on both pieces, that it has high initial tack and generally stays puts. He showed us that if one piece comes loose, it can be easily refastened. As he glued up these segments, Denny demonstrated yet another jig, this one to set the segment’s penetration into the interior of the piece, and to hold the intended angle. After the glue dries, the same router jig is used to set the layer thickness according to plan. The balance of the layer glue up reads like shampoo directions, lather rinse repeat. After the layers are complete, and sometimes in between sections, the inside and outside of the work can be turned. That was left for another day, as the session ran out of time.

Denny uses this software to design the bowl. It calculates the size and exact location of each segment.

Ready to flush the last layer.

Denny designed this jig to align the segments, but it required removing the bowl from the lathe for each layer. He moved on to another idea.

Another alignment jig that mounts to the bed of the lathe, this one works best.

This jig fits on the lathe bed to align each segment as it is glued to the layer.

Denny’s home made rig for flushing the end of each layer as it is glued to the bowl.

This meeting began with a brief presentation of the work of Malcolm Tibbitts, aka the Tahoe Turner. His web site is: http://www.tahoeturner.com/index.html . Take a peak there for some outstanding segmented turning and the inspiration for this night’s project, a melted bowl. Unlike previous segmented projects, in which the segments were glued together to make horizontal rings, tonight’s project will consist of horizontal rings that comprise the segments and that are then glued to complete the project. The preparation of the segments is critical to this project and that procedure is described in the following narrative.

Denny began with a more or less square block of wood; one could also glue cutoffs or scraps into layers and build up a piece for turning as well. He mounted this piece in his chuck and turned a socket for chuck mounting. He cautioned to leave as much square as possible. Using his dovetail chisel that matches the angle on his chuck he turned a recess on the tail end.

Turning a socket

He then chucked this recess in the headstock, effectively reversing the work piece and then made a socket in this end as well. He next used a parting tool to partially part off about ½” deep or so what will become the top of the melted bowl.

The workpiece was removed from the chuck and moved to the bandsaw at which point Denny said that the lid needed to be cut off, but not to cut it too straight. I thought that instruction would come naturally to me! The lid was labeled and set aside until almost the completion of the project.

The remaining block was sliced into layers, starting from the bottom and each layer was labeled with a number sequentially on either top or bottom, as to keep the grain pattern running through the piece when it is reassembled. Remember to not cut straight as the wavy cut is part of the design. Denny marked the approximate center on each piece and the pieces are moved to the drill press where small registration holes are drilled close to center, perhaps within an inch, and matching the diameter of an available wood dowel.

The future segments were then clamped slightly off-center and drilled about 1/4” deep with a forstner bit to facilitate chucking (his bit matched his chuck size so even though there was no taper, it could still be chucked.)

Each piece was remounted on the lathe and turned into somewhat of a donut shape, or call it a torus if you must. After turning, each piece was sanded on the outside and lightly on the inside where it will mate with an adjacent piece. Be careful to avoid sanding away the sawing irregularities. These pieces will become the segments. Each progressive piece was turned slightly smaller than its predecessor. Also, more wood was removed from the top of each segment than from the bottom.

The alignment holes were slightly countersunk to make inserting the dowel easier. The dowel was inserted and the segments were glued up around the perimeter, keeping the sequence. Once the glue has cured, rechuck the work to hollow it.

Stacking them up with off set centers

Denny started with a ¾” forstner bit mounted in the tailstock to begin the hollowing process. He would allow the bit to lightly find its own center, then lock down the tailstock, and advance the tailstock and bit into the work. Lathe tip and technique: remember to hold onto the chuck as it is withdrawn from the work as only a friction fit in the number two Morse taper holds the chuck (and bit) in place. Clear the shavings and redrill as needed. Denny drilled all the way up to 2” diameter with a forstner bit increasing the size in stages.

Turning the inside

With the work still securely mounted, Denny choose the round cutter on an Easy Wood Tool http://www.easywoodtools.com/ , but other tools could be used as well. In addition, Denny ran his lathe in reverse, so he could cut on the far side of the piece and void having to position his body so far over the lathe bed. Here he cautions to measure the thickness critically since the piece will not have a uniform thickness all the way around since some of the drilling was done off center. Once the piece is hollowed, Denny moved on to the top.

Now turn the top

The first job with the top is to turn it round, and then turn a section to fit inside the bottom. He lightly held the bottom against the spinning top to mark the diameter and turned it to size. He also hollowed the top for a nicer appearance.

The bottom was remounted and the lid was placed on top. The very top of the lid was turned and sanded. Denny says the project is a good candidate for spray lacquer.

Denny Wetter once again proved himself the ring master as he demonstrated turning wooden bracelets using segmented pieces, in much the same method used to make wooden bowls. As usual he starts with a drawing. The purpose of the drawing is to firm up the original idea for a bowl or bracelet and to determine initial lengths to cut the segments. Some trial software is available here :

Other sources are available on the web, either for free, as a trial, or for licensing. Denny’s favorite pattern has twelve segments, and one may come close to finding segment lengths by drawing a circle slightly larger than the diameter of the base, all the way up to the diameter of the top of the bowl. Of course the diameter needs to be larger that finished dimensions, to allow some room to true up and turn the piece. Denny pads his diameters by at least ¼ “. His favorite is to use ¾“ thick stock, even using cutoffs of some unique wood species. A twelve sided segment will show segment joints that correspond to the hour marks on a clock, as a point of illustration. Where segments meet, the pieces form a 30 degree angle, meaning each piece is cut at 15 degrees.

Can you count the layers in this one? Wow

Table saw sled for cutting 12 segmented circle. Once you get it perfect, don’t change it!

Denny uses a custom made jig to insure the same segment length for each of the same segments on each layer. Progressing up the bowl from the bottom, the segments get longer to accommodate the lager diameter of the upper layers of the bowl. Also, Denny’s jig allows very small adjustment of the angle cut on the end of the segments. The angle adjustment can be a trial and error process until suitably tight wood joints are achieved, but an initial setting of 15 degrees is the place to start.

Back of sled has two runners

For those who have attended the Tampa Wood Show and watch the “Dubby” being demonstrated, that is an indicator of the repeatability needed to produce segments. Jerry Cole has placed a video on You Tube that can give a good indication of what is attempted in explanation here:

//www.youtube.com/embed/t8yiXydcQN4

Denny uses a zero clearance insert to help prevent chip out. After cutting, the pieces are gathered, glue applied, and the pieces are clamped with ordinary hose clamps (think radiator hoses) joined end to end until a sufficient length is reached. You may get lucky, after your first twelve test cuts, or like most common people, your angle may a little adjustment. Test cuts may be made on squared up scrap and later used as kindling if needed. A small variation can be concealed by gluing up two sets of six pieces—a half of the intended diameter, and then sanding the remaining mating pieces on a disc sander to make it fit! Mark both the top and bottom of each piece and place one half on top of the other and sand together, so that when the pieces are correctly aligned, any variation in sand angle of one piece will cancel out with the other. One may need to try this to see how it works. Glue will fill some gaps, but keep the gaps tight if possible.

Denny cautions that segmented bowl bottoms can crack and shrink with changes in humidity and through drying. An alternative is a bowl bottom made out of strips keeping most expansion in one direction. Use contrasting woods if desired. This bottom piece needs to be sanded flat.

The glued up segment pieces need to be flattened as well. Denny showed three methods. One way is to sand the pieces flat on the sanding disc, being careful to hold the entire piece against the spinning disc.

Stack up each layer after sanding top and bottom flat.

Use large hose clamps to hold glued segments.

Alternatively mount a melamine work disc to a faceplate and hot melt glue the segmented diameter to the work disc and turn it flat or sand it flat using sandpaper glued to a flat working board. The third method is to mount the rough segment all the way against the face of the chuck and then flatten with the bedan tool. Also, pencil lines can be marked on all the segments and one can sand until all the lines are gone. In any case, put a straight edge against it and check it for flatness by looking for light between the piece and the straight edge.

Now, since this meeting is actually about turning wooden bracelets, but by point of illustration includes a generalization about cutting segmented bowls, Denny proceeded to show how to make bracelets. He begins with a 2 3/8” forstner bit at 500 rpm. He mounts the bit in a chuch in the tailstock and slowly advances it into the bracelet. (Lathe tip; remember to hold onto the chuck as it is being withdrawn as it is only held in place by the friction of a morse taper.) Then he cleans us the outside with a bedan. Next it is back to the inside with a round nose scraper. This first piece was made of contrasting cedar and pine and he sands the inside and outside. Then he removes the piece with a chisel against the hot melt glue.

The free piece is remounted on the expanding Nova chuck, or it can be mounted on a custom fitted nylon soft jaw accessory to the Nova chuck. Denny’s expanding soft jaw has a grove in it to hold the bracelet. Once mounted, he matches the other side. For this one he burned rings on the pine. Steel wire can be used to burn rings, but don’t hold the steel wire by wrapping it around your finger. Not only does it get hot, but a catch can pull your whole hand and more into the lathe.

Denny shared his secret of very thin bracelets. First one make rings as described, and then ¼“ thick sections are parted off. Hollow out just slightly wider than the parting tool. After the pieces come off the lathe, flatten the remaining part with a sanding board. Thin pieces can then be glued together in interesting patterns and turned to make up the bracelet.

Can you count the layers in this one? Wow

Five layer bracelet.

Three layer bracelet.

So many beautiful variations.

Stay tuned next month for another lathe episode of “As the World Turns.”

Since it is only 6 more months till Christmas Denny decided it was time to start working on decorations. The pictures speak for themselves.

The July 2014 woodturners’ meeting was highly influenced by PBS’ Create network which has a new show featuring woodturning with Tim Yoder. The episode that inspired Denny was one of making a showman out of wood, in this case mahogany.

1.) Denny began by roughing out a cylinder with a 1” roughing spindle gouge.

2.) He dimensioned at three places using a parting tool, and floowong his drawing, he marked where the snowballs intersected.

3.) He offered the tip to work towards the chuck when possible.

4.) A bedan was used to size the snowman’s hat, but a pointed parting tool could alternatively be used.

5.) He trimed the brim of the hat.

6.) Next he used a parting tool to mark the body divisions.

7.) The round “snowballs” were rounded with a bowl gouge.

8.) He alternated between the bedan and bowl gouge to form the three round bodies.

No snowman would be complete without sticks for arms, so Denny used a technique employing multiple centers to form the sticks.

1.) He use two pieces about the size of a pen blank, about 4” long.

2.) The first segment was made by deliberately not choosing the center of the wood.

3.) After roughing, the speed was increased a lot, because in Denny’s words, “We are turning a lot of air.” For this he used a small spindle gouge.

4.) When the first segment was turned impossibly thin (IMHO,) the center was changed, a different wobble was introduced to the piece, and the next segment was turned down, at an angle to the first segment. The wobble makes the joints in the arms.

5.) Denny also offered that the arms could be glued of different pieces.

A short conical piece was turned and colored with a carrot colored marker and glued on for a nose. Black dots were offered for the buttons. The corn cob pipe was done in separate sections, because as everyone knows corn cobs have a rough texture. For this, Denny used an old box cutter knife as a texturing tool for the corn cob. A short stem was made and the corn cob pipe body was drilled out for the pipe stem.

Denny later sanded the finished the snowman being careful not to use too much friction on the finish, as to avoid melting any of the pieces.